It is already known to introduce solutions of certain agents for controlling pests, or "pesticides" (in particular insecticides), into trees by means of so-called trunk implantation (cf. J. Econ. Entomol 61 (1968), 778-783; loc. cit. 64 (1971), 1295-1298; loc. cit. 72 (1979), 51-54; loc. cit. 81 (1988), 1668-1671; U.S. Pat. No. 4,342,176).
It is also known to use such active compounds, incorporated into solid shaped articles, for controlling pests on certain plants, in particular on trees (cf. EP 564945, JP 58039602--cited in Chem. Abstracts 98: 193401).
There is furthermore known a device for the transcuticular application of active compounds to plants in the form of an active-compound support which stores the active compound (cf. EP 254196). Upon use, however, this active-compound support is located on the surface of the plant and not inside the plant.
There is also known a method, or device, for applying herbicides to trees, in which the active compound is introduced into the tree via a sort of punch hammer (cf. U.S. Pat. No. 5,086,584). However, this application method is relatively complex; there was therefore a demand for a simpler use form for destroying undesired trees and other plants.
To destroy undesired plants, herbicides are furthermore generally employed in formulated form, that is to say combined with certain additives, with the aid of mechanical application equipment--in most cases spray equipment.
The task of removing undesired trees and shrubs from woodland or from gardens and parks is apparently gaining in importance. Performing this task with the aid of mechanical means is only possible on small areas in practice, and even that requires a great deal of labour, expense and technical effort. While the use of herbicides via spray application is technically feasible, it is unsatisfactory from the environmental angle.